Reaming and burnishing tool



. H. w. ZIMMERMAN annue AND BURNISHING Toor.

Filed Feb. 14, 1929 2 Sheets-Sheet l @12am/www@ 0t 18 1932- H. w.ZIMMERMAN 1,883,285

REAIING AND BURNISHING TOOL mea Feb. 14, 1929 2 sheets-sheet 2 FTW' Ff lI lY ,i 50@ l j f /9 2 ,A .il

IIN/@12 for I jferiiza l? ZzfZn 77261772022 Patented Oct. 4 18,l 1932.UNITED STATES PATENT OFFICE MAINTENANCE MACHINERY CO., ILLINOISREAMING- AND BURNISHING TOOL'y OF CHICAGO, ILLINOIS, A CORPORATION 'OF.Application filed February 14,1929. Serial No. 339,756.

My invention relates to reamers, and has to do primarily with tools ofthis character adapted for reaming connecting rod, and other, bearingssuch as are commonly employed in automotive construction.

One of the objects of my invention is to provide a greatly improvedreamer which is quite simple and inexpensive and which embodies aplurality of independent, blunt-face burnishing guides and a cuttingblade, the guides and blade being simultaneously eX- pansible andcontractible to the same extent, and the cutting blade being expansibleand contractible independently of the guides.

Another object is to provide areamer which is easy to operate, and whichinsures greater reaming accuracy, greater flexibility and ease inadjustments of the guides. and cutting blade, all of which greatlyreduces the time required for the reaming of bearings and, consequently,reduces the cost of such operations.

A further object is to provide a tool embodying the foregoing featureswhich may be readily and efficiently used by an unskilled workman asboth a burnishing tool and a reaming tool.

An additional object is to provide im# proved, accurate adjusting meanswhich is self-locking in any position of adjustment.

Other objects are to provide for positively positioning the burnishingguides and cutting blade against lateral and longitudinal displacementor disalignment; to provide for ready and quick removal of the cuttingblade and burnishing guides without disassembly of the tool parts,whereby replacements and repairs to these parts, and the tool as awhole, may be made very easily and quickly; to provide for a wide rangeof expansion and contraction of thecutting blade and burnishing guideswithout sacrificing strength, cutting accuracy and cutting ability; toprovide a reaming tool of the foregoing character wherein, once theprojection difference between'y the cutting blade and the guides isestablished, this difference need not be changed during the cutting of abearing, thereby eliminating the necessity o f repeated measurements ofthe bearing and tool and resetting o f the tool parts during the reaminof a bearing; and to provide a tool which wil effect a smooth cutwithout chatter or digging in.

Other objects and advantages will become 'in Fig. 1;

Fig. 4 is a. horizontal section taken substantially on line 1-4 of Fig.2;

Fig. 5 is a. horizontal section taken substantially online 5 5 of Fig.2;

Fig. 6 is a horizontal section taken substantially on line 6 6 of Fig.2;

Fig. 7 is a separated elevational view of the cone-spreader which'isadjustably associated with the cutting blade and burnishing guides forexpansion and contraction movements of the same.

Fig. 8 is a separated perspective view of a bar which is adjustablyassociated with the cutting blade.

The form of reamer which I have chosen to illustrate my inventionincludes generally a body 10 which rigidly supports a plurality ofburnishing guides 1l and a cutting blade l2 for expansion andcontraction movements, such movements being effected by longitudinaladjustment of a cone-spreader 13 which is so adjustably associated witheach of the guides and the blade that they may be simultaneouslyadjusted, each to the same extent. The cutting blade is adjustableindependently of the guides 11 by means of the slide bar 14 (Fig. 8)controlled by the nut l5.

Specically, the body 10 is provided with a cylindrical bore 10a eXtendinthroughout its length. The mid-portion of this body is provided with aplurality of equi-distant, radially extending rectangular slots 16 (Fig.6) which snugly receive the burnishing guides 11 for radially slidingmovements. The body is also provided with a slot 17, similar to theslots 16, which receives the cutting blade 12. The body is grooved at18, in front of the cutting blade 12, to provide a chipreceptive space.i

The burnishing ides and cutting blade are provided with at sides andstraight end edges which have snug sliding engagement with thecorresponding surfaces of the body slots 16 and 17, thereby effectingrigid suport of the same, and .longitudinal displacement ordisalignment. This is a necessary practical requirement in a tool ofthis character to provide maximum accuracy and true-cutting efficiency.The outer edges or faces of the burnishing guides are blunt, and theyare rounded to approximate the shape of the bearing surface with whichthey contact so that they have no effect upon the bearing surface exceptto burnish and guide the tool in the bearing. The cutting blade isprovided at its outer edge or face with a cutting edge 12. The inneredges of the guides 11 and blade 12 are each ltapered longitudinallyinthe same manner and to the same extent to provide for simultaneous,identical spreading and contracting movements of the same as will beexplained more fully hereinafter.

The cone-spreader 13 is received within the cylindrical body bore andit, preferably, takes the shape shown in Fig. 7. Specifically, it isprovided with a. lower cone-shaped portion 19 which is taperedcomplementally to taper of the inner edges of the burnishing guides andcutting blade. Cylindrical guide-bearing portions 20, 21 are provided atthe opposite ends of the tapered portion 19, and these cylindricalsurfaces snugly engage the cylindrical bore of the body for guidedmovement of the spreader 13 therewithin. The burnishing guides areyieldably supported in their body guide slots with their inner edges inengagement with the cone-surface 19 by spring rings 22 mounted ingrooves 11a at their opposite ends. The cutting blade 12 is, likewise,operatively associated with the cone 19 as will be more specificallydescribed hereinafter. The upper or outer end portion 23 of thecone-spreader is reduced and externally threaded to receive theadjusting nut 24.

The nut 24, while being free to rotate, is held against longitudinaldisplacement as follows: It is provided with a depending, reducedcylindrical portion 24a (Fig. 2) which extends into the upper, enlargedend 10" of the body bore and the larger, knurled portion 24b of this nutseats upon the top edge of the body. A circumferential groove 25 in thedepending part 243L of the nut freely receives the inwardly projectingends of the diametrically opposed,'bodycarried pins 26. It is obviousthat with this arrangement the cone-spreader 13 may be moved longitudiatall times, against lateral nally in a direction dependent upon thedirection of rotation of` lthe nut. Non-rotation -of the cone-spreaderduring the foregoing adjustment is accomplished by providing in itsreduced portion 23 a longitudinal slot 27 which freely receives theinwardly projecting end of the body-carried pin 28.

Adjustment of the cutting blade simultaneously with and independently ofthe burnishing guides is accomplished as follows: The cone-spreader isprovided with a radial longitudinal straight-Walled slot 29 (Figs. 2 and7) extending throughout its length, which slot receives the cuttingblade support bar 14 (Figs. 2 and 8). The inner edge 30" of this bar isstraight and seats and slides upon the inner straight-Walled surface ofthe spreader slot 29. The other edge of the lower part 30b of this baris tapered similarly to the taper of the adjacent cone surface of thespreader 13, and the spreader slot is of such depth that when the bar 14assumes the position therein indicatedin Fig. 2, its outer edge surfacewill lie flush with the adjacent tapered surface of the spreader. Theupper or outer portion of this bar 14 is reduced in width as at 30c sothat such portion will lie beneath the threads of the reduced spreaderportion 23 and will not interfere with rotative adjustment of the nut24. The outer end of the bar 14 has a lateral bifurcate extension 30dwhich embraces the adjusting nut 15 mounted upon the reduced threadedend of the spreader,- exteriorly of the adjusting nut 24. The taperedsurface of the bar 14 is complemental to the taper of the inner ed e ofthe cutting blade and the cutting blade is, obviously, pendently of theburnishing vguides 11 by merely rotating the nut in the desireddirection. The spring rings 22 hold the cutting blade frictionallyengaged with the tapere edge of the bar 14. The spreader bearing isrecessed into the s reader slot 29 at 31 (Fig. 7.) to provide a chamberwhich receives a spring 32. This spring, in the assembled position ofthe tool, seats upon the bar 14 to insure proper seating of the latterin the slot 29 at all times". The upper portion 24b of the nut 24 isrecessed to receive the bifurcate extension d on the bar 14 and permitthe nut 15 to be moved down against the nut 24.

When it is desired to dress a bearing, the operator may first determinethe extent of cut which should be made in the bearing. The tool is theninserted in the bearing (if it is not already there) and the nut 24 isadjusted counterclockwise (looking at Fig. 3) to move the spreader 13inwardly and expand the burnishing guides (and cutting blade) into snug,guiding engagement with the bearing surface. The nut 15 is rotated in aclockwise direction to project the cutting edge of the blade 12 say .001inch beyond the contractible and expansible indefaces of the burnishingguides. The bearing during the reaming of cut requires.

is then rotated u on the tool to make a .001 inch cut. The ad) tated toexpand the burnishing gui es into guiding engagement with the enlargedbearing surface, the .001 inch difference-projection of the cuttingblade remaining constant, and the bearing is again rotated. Thisoperation is repeated as many times as the total It is obvious that oncethe operator has made hisl preliminary measurements, no furthermeasurements are required the bearin The dif` ference-projection of thecutting blade determines the amountof cut each time, which amountremains constant due to the arrangement' wherein the cutting blade andburnishing guides are simultaneously adjustable to the same extent. Thisgreatly reduces the time required for reaming a bearing, consequentlyreducing the cost of the operation. By using the cone-spreader forexpanding the guides and blade, this operation is positive and accurate.The contracting movements of the guides and blade are, likewise,positive due to movement of the spreader to release these guides andblades and permit the spring rings 22 to move the same inwardly againstonly the friction offered by the body slots 16 and 17. Only a few partsare required for effecting these advantageous adjustments. The cuttingblade and burnishing guides are mounted independently of each other andseparately from their adjusting mechanism, so' that they may be readilyremoved and replaced Without disassembly of the tool. The cage-like bodyWith its thickwalled slots provides a rigid support for the cuttingblade and guides, and prevents displacement of the same in anydirection, at all times, all of which is desirable in order that thetool perform efficiently and rapidly to cut a smooth and approximatelytrue-cylindricalr surface.

After the desired cut has been made, the nut 15 maybe rotated in acounterclockwise direction (looking at Figs. 2 and 3) to retract theedge of the cutting blade to a point where the faces of the burnishingguides project therebeyond. The bearing may then be turned upon the toolin contact with only the faces of the burnishing guides to burnish andfinish the cut bearing surface. The burnishing guides may be adjustedduring this burnishing operation by rotation of the nut 24 withoutaffecting the projection-difference between them and the cutting blade.

It will .be obvious that while I have shown and described only two formsof my invention, other changes in the details and arrangements of theparts thereof may be made without departing from the spirit and scope ofmy invention as defined by the claims which follow.

I claim:

1. In a device of the class described, a body,

justing nut 24 is a ain romember having a threaded extension projectingthrough and beyond one end of said body' where it is constantlyaccessible, an adjusting device rotatably fixed in the latter-mentionedend of said body and engaging said threaded extension for longitudina lyadjusting said expander member relative to said guide element, saidexpander member having a longitudinal groove along one side the base ofwhich is substantially parallel with the axisv of said expandermember,an adjusting element o f substantially the outline shape of said grooveseated in said groove and adjustable to a position wherein its outeredge coincides with the cone-surface of said expander member, the outeredge of said element being engageable with a complementally-shapedportion of said blade, and means carried by said expander for slidingsaid element longitudinally in said groove to project its outer edgeVoutwardly beyond the cone-surface' of said expander member toindependently project said blade relative to said guide elements.

2. In a device of the class described, a body having a central spacewith passages leading outwardly therefrom, a bore-engaging cuttingIblade mounted in one of said passages, bore-engaging guides mounted inother of said passages, a cone-shaped member slidably mounted in saidcenter space and having its cone-surface engaging complementally shapedportions of said guides,means preventing rotation of said member in saidbody, an adjusting device screw-threadedly engaging said member androtatably mounted on said body so as to be confined against longitudinalmovement for adjusting said member longitudinally in said body, saidmember having a longitudinal groove therein the base of which issubstantially parallel with the axis of said member, an adjustingelement having a. straight edge seated in said tudinally slidabletherein and having its opposite edge tapered complementally to the taperof said member, the tapered edge of said element engaging acomplementallytapered portion ofy said blade, and another adjustingdevice rotatably connected to said element against relative longitudinaldisplacement, which other device screw-threadedly engages said memberfor moving said element longitudinally back and forth in said groove.

3. In a device of the class described, a-body, a cutting blade and guideelements slidably supported by said body for expansion or contractionmovement, a cone-shaped expanding member mounted in said body forlongitudigroove and longinal Asliding' movement only and engagingcomplementally-shaped portions of said guide elements, a.long1tudinal-axially-dii'ected groove in said expanding member which hasits base portion substantially parallel with thexis of said expandingmember, an adjusting element mounted in said groove and havingsubstantially the same outline shape and dimensions as said groovewhereby the outer edge of said adjusting element may assume a positioncoinciding with the conesurface of said expanding member or may beprojected outwardly therebeyond by longitu- `dinal sliding movement ofsaid adjusting element in said groove, means for adjusting saidexpanding member longitudinally in said' body without changing thethen-existing relative positions of said adjusting element and saidexpanding member, and means for independently adjusting `said adjustingelement' relative to said expanding member, said cutting blade having asurface complementally shaped to and engaging the outer tapered surfaceof said adjusting element whereby said cutting blade is expanded in saidbody as said expanding member is adjusted and as said adjusting elementis independently adj usted.

In testimony whereof, I have subscribed 30 my name.

HERMAN W. ZIMMERMAN,

